A “classic case” of failed communications was the single biggest mistake leading to the blow up of the Challenger space shuttle on Jan. 28, 1986, according to one who tried to prevent that fateful launch.

“It is not safe to fly based on what you don’t know,” Allen J. McDonald, who was director of the project on the day of the tragedy, stressed in a recent seminar at The University of Tennessee Space Institute.

People like to hear what they want to hear, the retired Thiokol executive added, noting also that about a dozen fellow engineers kept silent during the Presidential Commission and U.S. Congress investigations into the failed mission.

“They agreed with my position, but none of them stood up; they were afraid they might be wrong.” Had they joined him in protesting the launch on the cold January day, he thinks the Challenger would never have been launched.

McDonald stood fast in opposing the launch because of concern that unusually cold weather (for Florida) threatened reliability of O-ring seals on the shuttle but was overruled by NASA officials. While no one expected it, the seals failed, leading to the mixture of liquid hydrogen and oxygen and the explosion.

He also cited numerous examples of “Murphy’s Law” about things going wrong that plagued the mission.

UTSI Professor Gary A. Flandro introduced his long-time friend, who is a “Distinguished Lecturer” for the American Institute of Aeronautics and Astronautics (AIAA).

It was McDonald who revealed before the Presidential Commission that he had advised NASA to halt the launch. While this role eventually cast him in the light of a “hero,” the speaker said any good feelings about that were not as lasting as the regret of knowing “what might have been.” He acknowledged that his subsequent successful efforts to ensure that the O-ring problem would never occur again was satisfying.

While his testimony resulted in a demotion, he held various engineering and management positions during the 42 years before retiring in August 2001 as vice president and technical director for advanced technology programs for ATK Thiokol Propulsion.

Speaking directly to UTSI’s graduate students, McDonald advised: “You need to be professional. Use all the information in the room and make sure everybody participates – ask questions. There are no dumb questions.”

He noted that technicians assessing ice on the shuttle found temperatures as low as nine degrees on the morning of the launch and recorded these on charts but never shared this information.

The speaker noted that until the Challenger’s tragic fate, the U.S. had not lost any astronauts on a mission into space and pointed out that this was a most unusual mission because of the cross-section represented by its crew, including the first woman and first civilian to fly on the shuttle and that the public didn’t realize the danger.

NASA was apparently under pressure from the Reagan administration to proceed and the decision to go ahead with the launch was not an engineering management decision, McDonald emphasized.

McDonald pointed out that the loss of the Challenger was particularly significant at that time because “the shuttle was our key vehicle, and the Cold War was still going on in 1986, and we had lost every major launch vehicle we had within a year.”

Allen J. McDonald, center, shares a laugh with Prof. Gary A. Flandro, left, and John E. Caruthers before presenting a seminar at UTSI on the Space Shuttle Challenger tragedy and his efforts to halt that launch.